Taking folic acid before next blood test - Pernicious Anaemi...

Pernicious Anaemia Society

32,672 members24,065 posts

Taking folic acid before next blood test

Roo32 profile image
17 Replies

Hello all, first time posting here. I have just had my loading doses and during the appointment when I was told I was b12 deficient I didn’t manage to ask everything I should have it seems, particularly as it’s so hard to book doctors appointments as a self employed professional. The doctor told me I was also deficient in folic acid. She said we needed to get my b12 up before I had the folic acid prescription. I now have the prescription due to another doctor I saw in amongst my loading doses for a skin complaint, who said after the first three jabs it would be fine to take them. However, for reasons I won’t go into I don’t have total faith in this doctor. He was quite dismissive of the first doctors concerns for one thing. In any case in 2 months time I will be having another set of bloods taken and my main concern is, will taking my folic acid affect the outcome of these tests (ie skew the results, does folic acid interfere with the b12 levels being tested)? Neither doctor was clear about this and since the first didn’t prescribe the folic acid just told me I would need it later, I am unsure and would hate to mess up what I know are fallible enough blood tests.

Written by
Roo32 profile image
Roo32
To view profiles and participate in discussions please or .
Read more about...
17 Replies
shal61 profile image
shal61

Hope you don't mind following your post as I have same concerns my gp no longer wants to give injections , told to go to chemist for tablet form, of B12 and folic acid . But feel terrible.

Shu61

Nackapan profile image
Nackapan in reply toshal61

Is this the post you thought was missing? Why has the doctor stopped your injections?

Go back if you unhappy or I'll.

If you have an abortion issue tablets won't work

shal61 profile image
shal61 in reply toNackapan

Yes I have lots to read from you and others hope it gets me somewhere thanks all.

fbirder profile image
fbirder

The first doctor was correct - you shouldn't take high dose folic acid with an untreated B12 deficiency. There are concerns that doing so can exacerbate neurological damage.

The second doctor is also correct. Halfway through your loading doses your B12 levels should be high enough so as to make those concerns unwarranted. So you should be fine to take the folic acid.

The prescription will probably be for 15 mg tablets. You don't want to take them for too long as high doses are also thought to possibly be harmful, even if there is no B12 deficiency.

Taking the folic acid will have no effect on the B12 test. But that test will be pointless because you've been having B12 injections - of course your B12 levels will be high. Ask the doc why they are wasting the NHS's money by running a test that the British COmmittee for Standards in Haematology deem unnecessary. (onlinelibrary.wiley.com/doi... - Page 501 "No further testing for cobalamin levels is required")

Gambit62 profile image
Gambit62Administrator in reply tofbirder

fbirder is 15mg a typo? thought the normal treatment for folate deficiency was 5mg?

in anycase - agree that it shouldn't be taken for longer than the prescription.

fbirder profile image
fbirder in reply toGambit62

Ooops, yes. I meant 5 mg.

Roo32 profile image
Roo32 in reply tofbirder

Thank you for your reply that’s really helpful. Can I ask, if I have been under treated (having had only 6 loading doses despite what I believe are neurological symptoms) could taking folic acid before further treatment be damaging then?

I will attempt to ask about the blood tests but I feel as though it’s pretty clear my thoughts about my treatment are, shall we say, unwanted.

fbirder profile image
fbirder in reply toRoo32

I would be quite happy with taking folate after the 6 loading doses. They will have got your levels very high.

I'm not quite sure why there are different recommendations for those with or without neurological symptoms. There seems to be no evidence that it is beneficial or harmful.

Roo32 profile image
Roo32 in reply tofbirder

Interesting. This makes sense since as I understand it, the improvements that are made due to treatment can take months to manifest, irrespective of further b12 injections. I assumed this was to do with it taking around three months for red blood cells to be renewed.

fbirder profile image
fbirder in reply toRoo32

Normally, a red cell has a lifetime of around three months. But if you've been suffering from macrocytic anaemia caused by low B12 then the body goes on a spree of making new cells as soon as it gets enough B12. It'll only take around 4 to 6 weeks for macrocytic anaemia to go.

Most of the symptoms of a B122 deficiency aren't caused by the anaemia. Indeed, Dr Hajo Auwerda spoke at the PAS conference last week and said that only about 5% of his patients with a B12 deficiency have macrocytic anaemia. facebook.com/search/top/?q=...

Roo32 profile image
Roo32 in reply tofbirder

Ah ok. I didn’t know this.

My platelets did test as large. Yet my levels were not that low - 160. This has confused me as well as I understand macrocytic to be ‘end stage’.

fbirder profile image
fbirder in reply toRoo32

Large platelets have nothing to do with macrocytic anaemia.

Roo32 profile image
Roo32 in reply tofbirder

That explains that then! Thanks again for all the above.

Roo32 profile image
Roo32 in reply tofbirder

Having checked - it was my red blood cell distribution width which tested low.

fbirder profile image
fbirder in reply toRoo32

A low RDW is nothing to worry about.

Low B12 or folate can cause larger red cells. Low iron can cause small red cells. A mix of the two can cause a mix of small and red cells - which will have an normal average size. So a normal Mean Cell Volume can hide problems.

The RDW measures the difference between the biggest and smallest red cells. If you do have a mix of large and small cells then the RDW will be large. Your RDW is small because your body is very good at making consistently-sized red cells.

br74649 profile image
br74649 in reply tofbirder

That's a new one on me, Is there research on this? I've always thought that injecting b12 is useless without supplementing folate, I've even heard of not starting b12 until the folate is high enough or b12 could cause folate to go even lower causing neurological symptoms etc.

fbirder profile image
fbirder in reply tobr74649

Both B12 and folate need to be present in sufficient amounts. But that doesn't mean that you have to supplement with folate if you have B12 injections. That is a myth spread by a particular FaceBook group. People eating a healthy diet should have plenty of folate. But the gastric atrophy that causes PA can also affect folate absorption, so a low dose - 400 mcg a day - supplement may be useful.

You should not supplement with folate if you have a B12 deficiency. It can exacerbate the neurological damage. Taking B12 with folate deficiency is not as harmful, possibly no more harmful that an ordinary person having a folate deficiency.

Having B12 injections will not cause folate levels to drop. It is true that the burst of red cell formation will increase the body's demand for folate. But not a lot. Folate is used in a lot of biological functions, so the body has a lot of it (the normal blood range for folate is around 10,000 pmol/L, for B12 it's about 300 pmol/L). And folate doesn't get used up in the reaction involving B12 - it is recycled.

More about B12 and folate here - b12science.com/B12Science/D...

Not what you're looking for?

You may also like...

Folic Acid

Hi, can anyone advise please, my son was diagnosed B12 deficient last year, had loading dose and...
KMC21 profile image

Treated for low B12 and now low folic acid

I was told I was B12 deficient at the end of June and was given the 6 loading doses and I’m now...
Yogijo profile image

Low B12 & Folic Acid

Hi I have just been diagnosed by my doctor as having low b12 and low folic acid. She said i need to...
Nobby profile image

Folic Acid 5mg too much?

Hello, My doctor prescribed me 5mg folic acid for 4 months because my red cell folate was low...
GastritisB12 profile image

Advice on folic acid

I was diagnosed with pernicious anaemia in nov last year . I am 65 years old and also have...

Moderation team

See all
Gambit62 profile image
Gambit62Administrator
Foggyme profile image
FoggymeAdministrator
taka profile image
takaAdministrator

Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.

Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.